Fermentation is one of the earliest natural processes involving food and its preservation that humans sought to control. The earliest puffed-up breads, wines, and cheeses likely occurred by chance, and results were scarcely uniform or predictable. Disconcerted by off-flavors and spoilage in beer, wine, and baked goods, early peoples learned to control microorganisms whose existence would not be demonstrated for centuries. But in that process of control, people lost some of the benefits of wild fermentation. Sandor Ellix Katz has experimented with Wild Fermentation, and his book explains to others how to take advantage of natural fermentation processes to produce bread, yogurt, cheese, beer, wine, miso, sauerkraut, kimchi, and other fermented foods. A gold mine for science-fair projects, Katz's work presents properly supervised young people ample opportunity to explore both the science and the art of fermented food.